A number of reciprocating electric shavers have been proposed in the past that include, for improving their quick shave performances, a plurality of cutter heads capable of rocking relative to the main body, thereby allowing the cutter heads to be maintained in close contact with the skin of a user.
For example, Japanese laid-open patent publication No. SHO 62-227395 discloses a shaver that is designed to allow a plurality of cutter heads to conform to the contour of a skin, even if the manner of shaving is varied, by providing a rotation axis near the upper end of a head block with the cutter heads such that the entire head block can rotate back and forth about the rotation axis. In the above construction, however, the rotation axis provided near the upper end of the head block results in decrease in distance between the rotation axis and an outer cutter in contact with the skin. This makes it hard to rotate the head block if the outer cutter is slantingly pressed against the skin with small pressure. Further, it is almost impossible in the construction to float the head block (i.e., to bias it upwardly into a rockable state). Therefore, the construction fails to sideways conform to the contour of the skin as well as to absorb, during shaving, impacts caused by, for example, unevenness at bone portions, and thus it may damage the skin as well as being uncomfortable in shaving.
Japanese laid-open patent publication No. SHO 55-86490 discloses a shaver that includes a plurality of cutter heads each independently floated for vertical movement by means of a respective spring such that, by the vertical movement of each of the cutter heads, the shaver can conform to the contour of a skin with unevenness as well as absorbing the impact. However, the above construction requires an initial load exceeding a predetermined value against the floating force (the upwardly biasing force by the spring) so as to hold down the overall oscillation of the cutter heads caused by drive of their blades. Thus, in order to conform to the contour of the skin, the cutter heads have to be pressed against the skin with a considerably large force. Further, if the outer cutter is slantingly pressed against the skin, the cutter head is not positioned perpendicular to the skin, thus failing to function effectively.
Japanese laid-open patent publication No. SHO 63-197484 discloses a shaver including a plurality of vertically movable cutter heads with a linkage coupling the cutter heads arranged adjacent to each other, such that one of the cutter heads moves up while the other moves down, for conforming to the contour of a skin. However, the above construction can hardly absorb an impact during shaving. Further, it cannot function effectively because the cutter heads fail to contact perpendicularly with the skin.
Japanese laid-open patent publication No. HEI 10-43443 discloses a shaver having cutter heads and a motor that are arranged to be movable as a unit in the front-rear, the transverse, and the vertical directions. However, the above construction has the fulcrum for movement of the cutter heads at the considerably lower part, thus failing to satisfactorily conform to the contour of the skin.
The present invention has been developed in view of the above mentioned problems, and it is an object of the present invention to provide a reciprocating electric shaver that allows all of the cutter heads to conform to the uneven contour of a skin in response to various ways of shaving, and that can absorb impacts caused by, for example, unevenness at bone portions.